DESCRIPTION (investigator's abstract): Family history of hypertension is a primary predictor of high blood pressure in later life. The principal goal of this application is to determine how 24-hour ambulatory blood pressure distinguishes between individuals with different family histories: 2 hypertensive parents, 1 hypertensive parent, normotensive parents. The investigators will also examine effects of family history of blood pressure in combination with other factors linked to elevated blood pressure and hypertension: job strain, social support and personality traits (i.e., hostility, unexpressed anger, anxiety, defensiveness). Effects will be evaluated on a work day and an off work day in 192 men and women, aged 22-50 years, in a broad range of occupations. The investigators hypothesize that ambulatory blood pressure during waking and sleeping hours will be highest in offsprings of 2 hypertensive parents, somewhat elevated in those with 1 hypertensive parent, and lowest in those with normotensive parents. Predicted blood pressure elevations as a function of family history are expected to be greater in individuals with any of the following characteristics: high job strain, anxiety, hostility, defensiveness, or low anger-out. Also, the combination of a personality trait such as high hostility (or high anxiety, high defensiveness, or low anger-out), high job strain, and a family history of hypertension (particularly with 2 hypertensive parents) should lead to greater blood pressure magnifications. All predicted blood pressure effects are expected to be further elevated during work days, whereas the presence of high social support is expected to moderate blood pressure elevations. By sampling serum lipids, insulin, and glucose and daytime and nighttime urinary catecholamines and cortisol, the investigators will evaluate the role of insulin resistance and the sympathetic nervous system in family history. Investigating healthy men and women at risk for hypertension will help identify variables associated with high blood pressure before the disease is fully manifested and enable early intervention through diet and life-style changes. Since hypertension is predictive of future coronary heart disease, stroke, and renal disease, lowering the blood pressure for individuals at risk for hypertension can result in decreased morbidity and mortality rates.